class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        string ret;
        int j = 0;
        for (int i = 0; i < strs[0].size(); i++)
        {
            char tmp = strs[0][i];
            for (int j = 1; j < strs.size(); j++)
            {
                if (i == strs[j].size() || strs[j][i] != tmp)
                    return strs[0].substr(0, i);
            }
        }

        return strs[0];
    }
};